The invention concerns an electromagnetic relay with an insulating material base member which forms a base. The base member has a hinged or spring armature magnet system with coil, yoke and armature as well as also contact assemblies. Connection pins for the coil winding and for the contact assembly are guided through penetrations of the base to the connection side of the relay. Also, a protecting cap is provided which encompasses the base.
In the case of known relays of this sort, in general no ground connection is provided for the parts of the magnet system. For particular applications, nevertheless, a ground connection is desired. For this purpose, in the case of current relays, the construction had to be designed for this possibility. Since the ground connection in the case where it is needed must lie in the connection pattern of the rest of the relay connections, its own perforation was provided in the base of the base member and, when needed, provided with a connection element. The assembly of this connection element, nevertheless, had to proceed in an early stage of the manufacturing together with the remaining connection elements for contacts and coil winding. For this reason, the entire manufacturing process had to be adjusted for the special case of this ground connection and also its own mounting had to be provided for the special embodiment.
It is an object of the invention to provide a ground connection for a relay such that it can be produced simply and inexpensively, and, when needed, can be attached onto the finished assembled relay. According to the invention, this is attained with an additional connection conductor which is connected electrically with the yoke and runs on the magnet system along the interior side of the protecting cap. This additional conductor is guided in a groove, which corresponds at least to the size of the conductor, along the exterior side and along the connecting side of the base to a pattern point and there is bent at a right angle for the formation of a connection pin.
By means of the construction according to the invention, the ground connection can be applied subsequently to the finished assembled relay before the application of the protecting cap. This is possible since the ground connection is guided, not through borings of the base member, but rather via grooves which lie on the outside. With the exception of these grooves, no consideration must be taken regarding the embodiment with ground connection during the total relay construction. In the normal embodiment of the relay, therefore, only the grooves which run along around the base need be provided, which grooves nevertheless do not change or influence the relay whether or not the ground lead is provided.
It is practical to use as a connection conductor a wire which is bent into the corresponding form, which, for example, can consist of tinned Argentan. The connection of the connection conductor with the yoke proceeds in a practical manner by means of spot welding upon welding ribs. In a further design of the invention, it can further be provided that the connection conductor serves as a coil connection in addition to the connection with the yoke. The case can occur in which, for two separated coil windings, a center tap is to be connected with the ground tap.